From WO 2004/068198, ways of manufacturing optical elements by replication are known.
From WO 2007/140643, it is know to use recombination in replication of optical elements.
US 2006/0170810 A1 discloses methods for forming lens patterns by forming lenses on pre-formed lenses.
From U.S. Pat. No. 5,536,455, it is known to manufacture lenses placed in the middle of pre-formed lenses.
WO 2009/023465 A2 discloses a way of placing lenses off-center on a semiconductor device, so as to have an optical axis of the lens coinciding with an optically active region which is placed off-center in the semiconductor device. It is suggested to manufacture such lenses using molding.